Amazon UK is listing them at £317, which is a price (for a spec) that I am far more comfortable handing over to sony then I ever could have been handing over to Jolla for the J1.

The difference in spec/quality is day and night!

Just want to know if there will in fact be SFOS pre-loads available for sale, or, whether it's simply a case of buy a stock Xperia X and have a (relatively) easy time loading on the officially supported image....?

But I'd wait before there's something concrete (eg. look at the FP2 thread), there's no indication how they'll roll out the AD component - will we finally be able to buy it in the Jolla store, or will it only be available to people who buy a device through the Jolla shop.

The Xperia X is 5". Do you really want a 6" screen? My Nexus 6 sits on a shelf because using it is impossible unless I sit down and dedicate my full attention to it.

Well, I'd take 6 over 5 any time. I have 4.5", 5" and 5.5" and have to say that 4.5" on Jolla is the worst experience outside of some basic functions.
But 5.5" would do. And even 5" is better than 4.5"

Even though they don't say it, I'd be very surprised if Jolla's engineers wouldn't soon be using Xperias themselves. Professional dogfooding combined with cooperation from a quality hardware manufacturer should give us a good result. Whether Xperias will be sold with SFOS or I need to install it myself doesn't really matter if the adaptation is good. The community ports are impressive, but for daily use I really want a phone with zero issues.